1. Area of the Invention
The present invention relates generally to medical devices and, more particularly, to a hinge system for an orthopedic means for assisting movement of body limbs which are in an infirm or partially infirm state. The invention is of particular utility in infant pediatric and upper extremity applications.
Devices of the type to which the present invention relate are normally referred to as “orthotic”. This name is based upon the fact that such devices operate to support or assist injured or infirm body limbs, as opposed to replacing a missing limb. Accordingly, the term orthotic, as used herein, is distinguished from the term prosthesis which generally defines an artificial device to replace a missing body part or limb.
The invention includes a type of orthotic device which operates by a pawl and ratchet, and resilient spring action, to permit a range of certain degrees (steps) of limited rotational movement of infirm limbs relative to each other in a manner intended generally to simulate normal motion of such limbs.
2. Prior Art
This invention is an improvement over that of my U.S. Pat. No. 4,502,472 (1985), and other patents that I hold. Orthotic devices will, typically, include a pair of relatively moveable support members attached respectively to different parts of the body, for example, the upper leg and lower leg; in addition, some form of articulation means providing a resilient, or other controlled or controllable interconnection, between the proximal and distal parts of such a support device, are inherent to an appropriate operation of such devices. For the operation of such devices, it therefore is desirable that any artificial joint means, whether resilient in character or step-advance rotational in character, be sufficiently robust to assist in the effective functioning of the affected limb, while avoiding excesses or insufficiencies of motion which might prove discomforting or injurious, while a certain degree of adjustability, versatility, and the like in the motion of the functioning of such devices, is desirable.
Although the basic function of an orthotic device is to support a limb or limbs, it is desirable to attain a certain limited motion and flexibility in predetermined directions. Thus a goal of orthotic devices is the provision of the fundamental support function while, as an advantageous addition, providing a versatility of motion that will resemble normal body motion. As an addition to enabling adequate support, range of motion, and adjustability to various positions, the orthotic device should be as simple as possible in its arrangement of parts so that ease of manufacture will be attained and the functioning of the device is convenient as possible. The invention also addresses ease of locking and unlocking at given step positions, reverse and forward ratchet locking, unobtrusiveness in appearance of the system, these all being long-felt needs in the art.